1. Field of the Invention
The present invention relates to nitrate esters of ten cyclodextrin polymers and the encapsulation of explosives therein to obtain energetic materials with high energy performance but with reduced sensitivity characteristics.
2. Description of the Prior Art
Throughout this application, various publications are referenced in parentheses by author and year. The disclosure of these publications in their entireties are hereby incorporated by reference to more fully describe the state of the art to which this invention pertains.
The military and aerospace community has an on-going interest in and need for energetic materials with high energy performance but with low sensitivity characteristics. It is advantageous to find energetic materials or composites which can be used to produce new propellants and explosives that are less sensitive to detonation due to shock, fire or fragment impact while providing the same or greater energy than similar nitrocellulose based gun propellants and explosives. A desensitization of explosives is described in U.S. Pat. No. 5,114,506 using nitrate esters of cyclodextrins and an energetic organic nitrate ester plasticizer. The desensitization arises from the ability of cyclodextrins to encapsulate explosives.
An improvement of this strategy is presented according to the present invention which contains the first disclosure of nitrate esters of cyclodextrin polymers. These nitrate esters of various cyclodextrin polymers provide high molecular weight materials having improved behavior in explosive formulations, leading to favorable processing properties. The synthesis of the starting materials (cyclodextrin polymers) are in part taught in the literature. In accordance with the invention, such polymers can be converted to energetics by nitration. Polymeric cyclodextrin nitrate esters can be used as possible components of shock-insensitive, high-performance energetics. These materials are also suitable as components of insensitive, minimum smoke-producing propellants.
In accordance with the present invention, cyclodextrin polymers are nitrated in order to produce novel cyclodextrin polymer nitrate esters. A further feature of the invention is the encapsulation of explosive materials in the cyclodextrin polymer nitrate esters with the resulting formation of highly energetic materials having relatively shock-insensitive characteristics.
As a further feature, the invention provides a new method to synthesize a linear tube of cyclodextrin molecules, by using a water swellable, polystyrene based resin for complex formation as a first step in the synthetic process.